If the father isn't there for the first 6 months of child rearing, but the mother, friends, family, and hired nannies are, is it clear that a child will face lifelong repercussions?
These aren't all-or-nothing effects. Kids are resilient and adaptable, and it's never too late to start building a relationship.
But it is a relationship. If dad hasn't been there in the past, kid's got no reason to go to him for comfort or guidance in the future. That starts at birth, with holding & skin-to-skin contact, and continues through daily caregiving.